1. Field
Embodiments of the present invention relate to an ultrasonic probe having improved resolution by changing a focal zone by modifying a shape of a backing layer.
2. Description of the Related Art
An ultrasonic diagnostic apparatus emits ultrasonic signals toward a target region of an object from the surface of the object and generates an image of the target region such as a soft tissue tomogram or a blood stream image using reflected ultrasonic signals, i.e., ultrasonic echo signals. Since the ultrasonic diagnostic apparatus is small and inexpensive, displays an image in real time, and provides high safety owing to no X-ray exposure, or the like, as compared to other image diagnostic apparatuses such as an X-ray diagnostic apparatus, a computed tomography (CT) scanner, a magnetic resonance imaging (MRI) apparatus, and a nuclear medicine diagnostic apparatus, the ultrasonic diagnostic apparatus is widely used for heart diagnosis, celiac diagnosis, urinary diagnosis, and obstetric diagnosis.
The ultrasonic diagnostic apparatus includes an ultrasonic probe to transmit ultrasonic signals to an object and receive ultrasonic echo signals reflected by the object in order to acquire an ultrasonic image of the object.
The ultrasonic probe includes an acoustic module. In this regard, a transducer may include a piezoelectric layer to perform interconversion between an electric signal and an acoustic signal while a piezoelectric material vibrates, a matching layer to reduce difference in acoustic impedance between the piezoelectric layer and the object thereby efficiently transfer ultrasonic waves generated by the piezoelectric layer to the object, a lens layer to focus ultrasonic waves proceeding forward from the piezoelectric layer on a predetermined point, a backing layer to block transmission of the ultrasonic waves proceeding backward from the piezoelectric layer thereby preventing image distortion.